get_pnl

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Despite no annotations, the description thoroughly discloses read-only nature, the output structure (realized + unrealized + fees per strategy), and an error behavior (engine_not_running idle response when no snapshot). This fully compensates for missing annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences covering purpose, usage, and behavior. No fluff, every sentence serves a purpose. Front-loaded with the core action in the first sentence.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers return values and error case. No output schema, but description compensates by listing realized/unrealized/fees. Doesn't mention output format or limits, but for a simple snapshot read, it's adequate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so baseline is 3. The description adds value by clarifying that filtering by strategy only affects the breakdown, not the total ('total still reflects the full snapshot'). This nuance is not in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Read PnL totals plus per-strategy breakdown' and gives concrete query examples ('what's my PnL', 'how is strategy X doing today'). It distinctly identifies the resource (runtime snapshot) and the action (read). Among 30+ sibling tools, none overlap in purpose, making it easily distinguishable.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly advises when to use: 'for what's my PnL / how is strategy X doing today'. It doesn't list alternatives or when NOT to use, but the context is strong enough for correct selection. Lacks explicit sibling differentiation, but the use case is narrow enough.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.